also received calls but they leave no message. I'm not picking up.

I received a call from this number.  Caller i.d. stated it was from Joplin, MO. They left no message.  I don't know who it is; therefore, I'm not picking up, either.

No positive, but pretty sure it's Mid-America Collection.

I'm sure it is a debt collector. They are calling my JOB.

I received a call but they did not tell me what they wanted.  If you receive calls at work read the fair credit act. It is illegal and you can sue for the harrassment when you are at work.  If they call you at home they must follow up with a bill within one working week or you can sue them for 1000. each call.